This invention pertains to a portable lathe usable on site for preparing the end of a pipe preparatory to an operation, such as welding another pipe thereto.
Many different forms of portable lathe are known in the art. A portable lathe embodies a frame which can be accurately secured to a pipe. A tool head rotatable on the frame has a tool slide with a tool which may be advanced during rotation of the tool head to perform a desired cutting operation on the pipe. The tool is advanced by means including a cam on the frame coacting with a cam follower carried on the tool head whereby contact of the cam follower with the cam during rotation of the tool head results in an incremental advance of the tool slide.
The motion of the cam follower has been transmitted to means associated with the tool slide for causing incremental movement thereof by various devices including a hydraulic line which delivers a pressure pulse to a hydraulic motor associated with the tool slide incremental advancing means or a Bowden wire which transmits the motion of the cam follower. The angle of the tool slide relative to the tool post can be varied in order to control the angle of the tool advance relative to the pipe end for setting a bevel cut on the pipe end. The hydraulic hose or Bowden wire is normally of sufficient length to accommodate the variation in the distance between the cam follower fixed to the tool head and the tool slide incremental drive means. The hydraulic hose or Bowden wire rotating with the tool head protrudes and can be hazardous to an operator of the lathe.